Sirens designed to alert residents who live near the Palo Verde Nuclear Generating Station west of Phoenix about radiation emergencies will be tested on Wednesday.
Officials say the 48 warning sirens placed in a 10-mile radius around the plant will be sounded for three minutes at noon and again 30 minutes later.
The Maricopa County Emergency Management Department would use the sirens if a nuclear emergency happened at the triple-reactor plant 50 miles west of Phoenix in Wintersburg.
The Arizona Department of Transportation will use electronic message signs to notify drivers on Interstate 10 of the test.
The siren tests are done once a year. Area residents are provided materials on how to respond in an emergency.